Fabrication and characterization of percolating nanocluster devices

We are reporting on the fabrication and characterization of palladium (Pd) nanocluster devices. Pd nanoclusters were synthesized inside a dc magnetron sputtering chamber, where the plasma vaporizes the target's material and nanoclusters are formed by inert gas condensation. The size distribution of the produced nanoclusters is investigated using quadrupole mass filter. To fabricate a device, nanoclusters are self-assembled on a SiO₂/Si substrate that contains a pair of pre-formed electrical electrodes defined by optical lithography. The electric current between the electrodes is monitored during nanoclusters deposition. A sharp increase in the current indicates the formation of a continuous network of clusters, thus, nanocluster deposition is abruptly stopped. Electronic transport of the device is investigated by systematic currentvoltage measurements as a function of temperature.